In the processing of chickens, turkeys and other types of birds through a poultry processing plant for defeathering, evisceration, cut-up and packaging for delivery to a retail grocery store, etc., it is highly desirable to perform as many of the processing steps as possible with automated machinery. It is important to minimize the amount of manual handling of the birds so as to minimize the expense of processing and to uniformly cut apart the birds.
The general trend in poultry processing in recent years has been to suspend birds by their legs from an overhead conveyor system and perform as many of the processing steps as possible as the birds are being moved in series on the conveyor system from one processing station to the next. For example, the birds can be decapitated, opened and eviscerated while being progressively advanced along an overhead conveyor system. Additionally, it is desireable to cut apart the birds while they move on an overhead conveyor system to avoid the manual handling of the birds while the cutting functions are being performed. A cut up system of this type is disclosed in my prior U.S. Pat. No. 4,574,429. However, it is still common practice to first remove the birds from the overhead conveyor system prior to cutting them apart.
One of the problems with the prior art poultry cut up machines of the type that cut the birds while the birds are suspended from an overhead conveying system is that it is difficult to accurately position and maintain the birds in alignment with the cutting elements of the cut up machine so that proper cuts are formed in the carcasses. When birds of different sizes enter the machine, the larger or smaller birds tend to approach the cutting elements at positions that are too low or too high for the cutting elements.
Some prior art processing systems have been developed that use mandrels to support the birds during the cutting steps. A cut up system of this type is disclosed in my prior U.S. Pat. No. 4,559,672. The birds are each positioned with their previously eviscerated visceral cavities mounted on a mandrel. This supports the carcass at a predetermined position without regard to the lengths of the legs of the birds, and the mandrels tend to expand the skeletal elements of the bird to a shape corresponding to the mandrel. However, most of the poultry cut up machines that use mandrels require the birds to be mounted by hand on the mandrels.
Therefore, it can be seen that it would be desireable to provide an improved, reliable and accurate method and apparatus for removing the breast portions of previously eviscerated birds as the birds are moved in series along on overhead conveyor system.